Jar for drilling tools



' Nov. 15, 1932. L. 1.. HAZEN JAR FOR DRILLING TOOLS Filed June 20. 1929 Z Z lgvjg /enfw: 5 e @5677.

( @zj eL d Patented Nov. 15, 1932 UNITED STATES PATENT oFFicE f LYSLE L. HAZEN, J'OPLIN, MISSOURI I JAR, FORZDRILLING TOOLS Application filed June 20,

The present invention relates to tools for earth drilling by reciprocative or cable-drill methods, and has special reference to the jars which are frequently employed. The Q invention deals particularly with a novel the jars become more sensitive, effective'and durable than has heretofore been possible.

-Inthe reciprocative method of drilling an impact is given to the bit which is employed,

for example, by using a bit within the well and dropping thereon a stem or Weight sustransmitted to and along the cable by the j arring impacts of the two links 'of the jars, in

either the upward or the downward strokes thereof, as may be encountered in the various uses of the group of tools including jars.

The present invention "has reference to the construction of a set of jars which permits the use of a new type of impact surface whereby the jars become more sensitive, and also which permits employment of the special kinds of material in the jars which are re quired best to adapt specific parts of the tool to their specific functions. 8 1

One object of the invention is to provide a structure which permits selecting specially suitable metals for the special duties and stresses of the various parts. of the tool.

.Another objectis the use of a cross-sectional form for the reins of the links which permits'increased strength in the reins for the amount ofmetal emp1oyed,and places as much rein metal aspossible near'the outside portion of the tool. 1

Still another object is the use of flat or flat hardened metal impact surfaces.

Various other objects and advantages of construction of'the jars by virtue of which 8 1929. Serial No. 372,84

the invention will become apparent from the following description of the several exemplary embodiments shown in the accompanying drawing, in which F ig. 1 represents a set of jars;

Fig. 2 shows a longitudinal mid-section of the jars. of Fig. 1, as viewed from the left in Fig. 1;

Fig. 3 is a cross-section of Fig. 2 on line 33 thereof, showing'the knockinghead in on the upper link;

Fig. 4 is a cross-section of Fig. 2 on line 4+4 thereof, showing the knocking head in the lower link;

Figs. 5 and 6 are modified constructionsv of,

knockmg head mountings.

i Generally the jars which I have-chosenas the preferred embodiment of my invention comprise two telescoping links, each being bifurcated, and both having theirbifurca tions intermeshed, and interlocked by impact members closing the bifurcated ends. The four longitudinal elements thus formed are termed therein's of the jars. I In the drawing an upper'link is represented: by the numeral 10, and comprises a conical .threaded pin 11 at the upper end, a mass of stock providing'a stem 12, the stem beingprovided with opposing flat spaces 13 for application, of wrenches, and the two reins 14' and 15.' The link is generally cylindrical and the reins are arcuate on the outside and are coextensive with the round form of the stem 12. Each rein in arcuate extent is slightly less than a complete quadrant in order to provide aworking space 16-between adjacent sliding reins; The interior of the reins is cylindrically hollow, I providing arcuate surfaces 17 and 18.

The lower link may be similarly construct ed as to the formation of the reins, and is generally indicated by the numeral 20. It comprises in the present instance a link made fromtubular stock,"havin g a conical threaded end or box' 21, a stem portion 22'which is merely a hollow cylindrical member, slotted 'at 23 and 24 to provide reins 25 and26. The reins are preferablyidentical in cross-section with the reins 14 and 15 of the upper link.

Parallel flat surfaces 27 are providedon the stem portion for the application of wrenches.

Into the stem 12 of the upper link at the base of the reins is inserted a knocking head 30, having a flat surface 31. The knocking head is cylindrical and has an outside diameter which corresponds to the interior curvature of the reins. The exposed impact surfaces are cut away at the periphery as indicated at 32 so that the diameter of the exposed flat surface is less than the diameter \of the body.

The upper link carries at its lower end a cylindrical knocking head 34 (Fig. 3) secured between the reins 14 and 15 and very rigidly united with them. The knocking head is generally cylindrical in form with a fiat impact face 35. The head has two arcuate surfaces 36 and 37'which fit snugly against the inner arcs 17 and 18 of the reins. The alternate surfaces 39 and 40 have a less degree of curvature and provide clearance spaces 41 and 42 between them and the reins 25 and 26 of the lower link. Four guides or wings 43 are formed on the head and ride freely in the working spaces 16 between adjacent reins.

The lower link has a similarly constructed knocking head (Fig. 4) at theupper end between its reins 25 and 26. The two ends of the head 50 have flat exposed surfaces 51 and 52, each of which is slightly cut away at the periphery by annular grooves 53 and 54 to accommodate any burrs that may be formed by upsetting or stoving of the metal in usage as a result of the severe impacts to which the endsv are subjected. I

The knocking heads 34 and 50 may be unit- -.ed to the reins which carry them by various methods, such as the use of keys, flanges, rivets, welding or various combined means. In I Figs. 1 and 2 wedges 55 are shown extending across the reins and through theknocking heads. The wedges are heldin place by.

' welding the ends to the reins.

In Fig. 5 a modified construction is shown.

The knocking head is a tubular insert 57' welded to the reins. Upon and against the tubular insert there is a disk of hardened metal 58 pressed into place to provide the impact surface. I I I In Fig. 6 the knocking head comprises a cylindrical block 60 keyed in place in the reins by a. longitudinal key 61 and horizontal keys 62.

I-Ieretofore, jars have been provided with rounded impact surfaces, which are not efficient. The present construction permits the use of inserts as knocking heads and allows for impact surfaces.

for selection of material so that suitable hard and durable metal may be used, with fiat surfaces; or flat hard inserts may be used The life of the heads is thus increased and their efficiency and sensitivity for telegraphing impulses to the cable is also greatly increased. When welding is employed the metal must of course be I reins may then chosen for their welding characteristics as wellas their physical properties, and stresses produced by welding may require heat treatment to minimize or remove them. Consequently,'when the metals differ, they may be chosen with due regard for a simultaneous heat treatment. For these reasons, mechanical union of the inserts to the reins is preferred to welding. The inserts and the sectional form of the reins.

The jars of course are the weakest part of the tool group, as the outside diameter is limited to the bore, and the jar links mustbe bemade of the most suitable benefit to be obtained by reason of the crosshollow. By using the near-quadrant struc ture with internal and external arcuate surfaces, all the practically available space is utllized for rein metal, and greater strength and efficiency results from use of the in; creased quantity of metal. The particular near-quadrant form for each rein provides a greater quantity of metal at the largest diameter and hence the strength is correspondingly increased. In prior practice of construct. mg jars it is not possible by the. hammering methods employed to draw themetal into corner areas that are available. I

Thefull-section of the reins also provides increased wearing areas against the wall of; the well, and of one rem against another rem.

The primary objects of this invention are obtained by using the type of constructions disclosed, by machining or drawing the parts from well chosen solid or tubular stock, by, providing fiat, hardened impact surfaces, and

by mechanically uniting the heads in the reins.

' It is to be understood that the present invention is not'to be considered as limited to thespecific disclosures herein made for the purpose of illustration, and that it is to be consideredthat such changes and modifications may be made as fall within the scope of the appended claims. I

1. In a set of jars, a link having a pair of reins which are slightly less than quadrants in arcuate extent, a knocking head connecting the reins at a region along the reins remote from the base of the reins, and pins extending from one rein to the other rein through said knocking head for mounting the head to said reins. I I I 2. In a set of'jars, a link having reins provided with concentric arcuate inner and outer bounding surfaces, each rein being slightly less than a quadrant in extent.

3. In a set of jars, two links having intermeshed reins, the reins having outer arcuate surfaces circularly co-extensive, and

having inner arcuate surfaces circularly co' quadrant in extent, and a knocking head in each link between the link reins, the knock ing head having two surfaces with a curvature to correspond withthe inner curvature of the mounting reins and having two other 7 surfaces of less diameter to provide a sliding clearance with the other link reins.

5. In a set of jars, two links having intermeshed reins, the reins having outer arcuate surfaces circularly co-extensive, and having inner arcuate surfaces circularly co-extensive, each rein being slightly less than a quadrant in extent, and a knocking head in each link between the link reins,the knocking head having two surfaces with a curvature to correspond with the inner curvature of the mounting reins, having two other surfaces of less diameter to provide a sliding clearance with the other link reins, and guide wings projecting from the head into the spaces be tween the reins.

In Witness whereof, I hereunto subscribe my name this 17th day ofJune, 1929.

LYSLE L. HAZEN. 

